Electrical pulse stimulation-induced tetanic exercise simulation increases the secretion of extracellular vesicles from C2C12 myotubes

Extracellular vesicles (EVs) released into the blood during exercise mediate its whole-body health effects. The differentiation of EVs released by skeletal muscle cells in vivo from those released by other cells is challenging, therefore, it is unclear whether exercise increases the number of EVs secreted by skeletal muscle cells. In this study, we investigated whether exercise affects the quantity of EVs released from skeletal muscle cells using in vitro exercise models. C2C12 myotubes were cultured on a gel layer with 1 or 30 Hz electrical pulse stimulation (EPS) to induce contractions as an artificial simulating exercise. We found that tetanic contraction induced by 30 Hz EPS increased the number of secreted EVs. MicroRNA (miRNA)-seq analysis revealed that 30 Hz EPS altered the miRNA in the secreted EVs. Furthermore, expression analysis of genes related to the biogenesis and transport of EVs revealed that the expression of ALG-2 interacting protein X (Alix) was increased in response to 30 Hz EPS, and the peak value of intracellular Ca2 thorn in myotubes at 30 Hz EPS was higher than that at 1 Hz, indicating that the increase in intracellular Ca2 thorn concentration may be related to the increased secretion of EVs in response to 30 Hz EPS. & COPY; 2023 Elsevier Inc. All rights reserved.

Automated summary

Extracellular vesicles (EVs) released during exercise have health effects, but it is unclear if exercise increases the number of EVs released by skeletal muscle cells. This study used in vitro exercise models to investigate the effect of exercise on the quantity of EVs released from skeletal muscle cells. The results showed that tetanic contraction induced by 30 Hz electrical pulse stimulation increased the number of secreted EVs.